devel/py-dbus,devel/pydbus-common: update to 1.2.18

Changelog [1]:

Build-time configuration changes:

• dbus-python will be built for python3 if neither PYTHON nor PYTHON_VERSION is specified. Use a command like ./configure PYTHON=$(command -v python2) if installation for Python 2 (EOL 2020-01-01) is required.

Dependencies:

• Python 2 reached end-of-life on 2020-01-01. A future version of dbus-python is likely to remove Python 2 support.

Fixes:

• Move from collections.Sequence to collections.abc.Sequence on Python ≥ 3.3, for Python 3.10 compatibility (dbus-python#37; Simon McVittie)
• Avoid another deprecation warning for inspect.getargspec(). This is similar to the one fixed in 1.2.4, but for dbus.decorators.signal rather than dbus.decorators.method. (dbus-python!8; Martin Stumpf)
• Fix an unlikely fd leak if memory allocation fails for UnixFd (dbus-python!9, Red Hat #1938703; David King)
• Fix memory and fd leak if UnixFd is given an invalid negative variant_level (Simon McVittie)
• Avoid more deprecation warnings: - gi.repository.GObject.MainLoop etc. (now used via gi.repository.GLib) - gi.repository.GLib.threads_init (no longer necessary at all) (Simon McVittie)
• Disable -Wdeclaration-after-statement. Python 3.9 relies on intermixed declarations and statements in its headers, so we can no longer enforce this. (Simon McVittie)
• Convert examples to Python 3 (Simon McVittie)
• Use the same Python executable for build and dist/distcheck by default (Simon McVittie)

[1] https://dbus.freedesktop.org/doc/dbus-python/news.html#dbus-python-bindings-1-2-18-2021-07-20